Stockholders' Equity - Summary of Outstanding and Vested Options (Details) shares in Thousands	12 Months Ended
	Dec. 31, 2018 $ / shares shares
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Number of Shares Outstanding | shares	6,266
Options Outstanding, Weighted-Average Remaining Contractual Life (Years)	6 years 6 months 18 days
Options Outstanding, Weighted-Average Exercise Price (in dollars per share)	$ 12.13
Options Exercisable, Number of Shares | shares	3,278
Options Exercisable, Weighted-Average Exercise Price (in dollars per share)	$ 11.12
$1.79 - $7.60
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, minimum (in dollars per share)	1.79000
Exercise price range, maximum (in dollars per share)	$ 7.60000
Options Outstanding, Number of Shares Outstanding | shares	1,081
Options Outstanding, Weighted-Average Remaining Contractual Life (Years)	6 years 4 months 13 days
Options Outstanding, Weighted-Average Exercise Price (in dollars per share)	$ 7.03
Options Exercisable, Number of Shares | shares	570
Options Exercisable, Weighted-Average Exercise Price (in dollars per share)	$ 6.70
$7.95 - $9.55
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, minimum (in dollars per share)	7.95000
Exercise price range, maximum (in dollars per share)	$ 9.55000
Options Outstanding, Number of Shares Outstanding | shares	635
Options Outstanding, Weighted-Average Remaining Contractual Life (Years)	5 years 10 months 24 days
Options Outstanding, Weighted-Average Exercise Price (in dollars per share)	$ 9.20
Options Exercisable, Number of Shares | shares	488
Options Exercisable, Weighted-Average Exercise Price (in dollars per share)	$ 9.18
$9.90 - $10.13
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, minimum (in dollars per share)	9.90000
Exercise price range, maximum (in dollars per share)	$ 10.13000
Options Outstanding, Number of Shares Outstanding | shares	640
Options Outstanding, Weighted-Average Remaining Contractual Life (Years)	5 years 4 months
Options Outstanding, Weighted-Average Exercise Price (in dollars per share)	$ 10.09
Options Exercisable, Number of Shares | shares	636
Options Exercisable, Weighted-Average Exercise Price (in dollars per share)	$ 10.09
$10.31 - $11.96
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, minimum (in dollars per share)	10.31000
Exercise price range, maximum (in dollars per share)	$ 11.96000
Options Outstanding, Number of Shares Outstanding | shares	660
Options Outstanding, Weighted-Average Remaining Contractual Life (Years)	6 years 9 months 8 days
Options Outstanding, Weighted-Average Exercise Price (in dollars per share)	$ 11.26
Options Exercisable, Number of Shares | shares	388
Options Exercisable, Weighted-Average Exercise Price (in dollars per share)	$ 11.00
$12.09 - $12.32
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, minimum (in dollars per share)	12.09000
Exercise price range, maximum (in dollars per share)	$ 12.32000
Options Outstanding, Number of Shares Outstanding | shares	39
Options Outstanding, Weighted-Average Remaining Contractual Life (Years)	2 years 3 months 22 days
Options Outstanding, Weighted-Average Exercise Price (in dollars per share)	$ 12.29
Options Exercisable, Number of Shares | shares	39
Options Exercisable, Weighted-Average Exercise Price (in dollars per share)	$ 12.29
$12.45 - $12.45
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, minimum (in dollars per share)	12.45000
Exercise price range, maximum (in dollars per share)	$ 12.45000
Options Outstanding, Number of Shares Outstanding | shares	930
Options Outstanding, Weighted-Average Remaining Contractual Life (Years)	9 years 1 month 18 days
Options Outstanding, Weighted-Average Exercise Price (in dollars per share)	$ 12.45
Options Exercisable, Number of Shares | shares	0
Options Exercisable, Weighted-Average Exercise Price (in dollars per share)	$ 0.00
$12.46 - $13.59
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, minimum (in dollars per share)	12.46000
Exercise price range, maximum (in dollars per share)	$ 13.59000
Options Outstanding, Number of Shares Outstanding | shares	684
Options Outstanding, Weighted-Average Remaining Contractual Life (Years)	3 years 5 months
Options Outstanding, Weighted-Average Exercise Price (in dollars per share)	$ 13.31
Options Exercisable, Number of Shares | shares	684
Options Exercisable, Weighted-Average Exercise Price (in dollars per share)	$ 13.31
$14.30 - $15.96
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, minimum (in dollars per share)	14.30000
Exercise price range, maximum (in dollars per share)	$ 15.96000
Options Outstanding, Number of Shares Outstanding | shares	678
Options Outstanding, Weighted-Average Remaining Contractual Life (Years)	7 years 2 months 18 days
Options Outstanding, Weighted-Average Exercise Price (in dollars per share)	$ 14.73
Options Exercisable, Number of Shares | shares	146
Options Exercisable, Weighted-Average Exercise Price (in dollars per share)	$ 14.97
$16.05 - $21.75
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, minimum (in dollars per share)	16.05000
Exercise price range, maximum (in dollars per share)	$ 21.75000
Options Outstanding, Number of Shares Outstanding | shares	770
Options Outstanding, Weighted-Average Remaining Contractual Life (Years)	6 years 10 months 5 days
Options Outstanding, Weighted-Average Exercise Price (in dollars per share)	$ 18.30
Options Exercisable, Number of Shares | shares	327
Options Exercisable, Weighted-Average Exercise Price (in dollars per share)	$ 17.45
$22.04 - $23.50
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, minimum (in dollars per share)	22.04000
Exercise price range, maximum (in dollars per share)	$ 23.50000
Options Outstanding, Number of Shares Outstanding | shares	149
Options Outstanding, Weighted-Average Remaining Contractual Life (Years)	9 years 6 months 22 days
Options Outstanding, Weighted-Average Exercise Price (in dollars per share)	$ 22.91
Options Exercisable, Number of Shares | shares	0
Options Exercisable, Weighted-Average Exercise Price (in dollars per share)	$ 0.00